(CNN) -- An image of the new United States ambassador to China trying to buy a coffee at an airport in Seattle has caused a stir in his adopted country.

Former U.S. Commerce Secretary Gary Locke was snapped by a passing Chinese traveler on August 12 at a Starbucks coffee shop without any security and carrying his own backpack as he waited with his family.

The traveler immediately uploaded the picture, taken on his iPhone, to Chinese micro-blogging site, Sina Weibo, where it was picked up by bloggers and the mainstream media alike in China. Within two days the image was re-posted more than 40,000 times.

They appeared to be impressed by the understated envoy's low key approach, which is in stark contrast to the tight security that typically follows senior Chinese diplomats.

"He's carrying his own backpack," exclaimed the Beijing Times, while the government-run Beijing Legal News observed that Locke's family "look like ordinary travelers."

Meanwhile, one blogger commented, "You people out of China might think this photo is too ordinary and can't see much out of it, but for Chinese it's shocking."

The author of the image, named by Sina Weibo as TangChaohui_adSage, later posted a message saying the Starbucks staff even refused Locke's attempts to exchange his discount coupon for a coffee, forcing him to pay with a credit card. This prompted some bloggers to joke that the U.S. must really be suffering economically if its ambassador was forced to use such a voucher.

Other bloggers simply praised Locke for being the kind of official they crave.

"This (Locke) is the model government official figure Chinese citizens wish for because China doesn't have officials like this," wrote one.

The outgoing U.S. ambassador to China, Jon Huntsman, won admirers in China for his informal style. He would often get around Beijing on his bicycle rather than the official ambassadorial limousine.